•  54
    The axiomatization of randomness
    Journal of Symbolic Logic 55 (3): 1143-1167. 1990.
    We present a faithful axiomatization of von Mises' notion of a random sequence, using an abstract independence relation. A byproduct is a quantifier elimination theorem for Friedman's "almost all" quantifier in terms of this independence relation
  •  106
    Algorithmic information theory
    Journal of Symbolic Logic 54 (4): 1389-1400. 1989.
    We present a critical discussion of the claim (most forcefully propounded by Chaitin) that algorithmic information theory sheds new light on Godel's first incompleteness theorem
  •  10
    Language Evolution: Enlarging the Picture
    In David McFarland, Keith Stenning & Maggie McGonigle (eds.), The Complex Mind, Palgrave-macmillan. pp. 264-282. 2012.
  •  26
    Gaisi Takeuti has recently proposed a new operation on orthomodular latticesL, $\begin{array}{*{20}c} \parallel \\ \_ \\ \end{array} $ :P(L)»L. The properties of $\begin{array}{*{20}c} \parallel \\ \_ \\ \end{array} $ suggest that the value of $\begin{array}{*{20}c} \parallel \\ \_ \\ \end{array} $ (A) (A) $ \subseteq $ L) corresponds to the degree in which the elements ofA behave classically. To make this idea precise, we investigate the connection between structural properties of orthomodular …Read more
  •  3054
    A formalization of kant’s transcendental logic
    with Theodora Achourioti
    Review of Symbolic Logic 4 (2): 254-289. 2011.
    Although Kant (1998) envisaged a prominent role for logic in the argumentative structure of his Critique of Pure Reason, logicians and philosophers have generally judged Kantgeneralformaltranscendental logics is a logic in the strict formal sense, albeit with a semantics and a definition of validity that are vastly more complex than that of first-order logic. The main technical application of the formalism developed here is a formal proof that Kants logic is after all a distinguished subsystem o…Read more
  •  56
    Formal models for real people
    with Marian Counihan
    Journal of Logic, Language and Information 17 (4): 385-389. 2008.
  •  156
    Semantics as a foundation for psychology: A case study of Wason's selection task (review)
    Journal of Logic, Language and Information 10 (3): 273-317. 2001.
    We review the various explanations that have been offered toaccount for subjects'' behaviour in Wason ''s famous selection task. Weargue that one element that is lacking is a good understanding ofsubjects'' semantics for the key expressions involved, and anunderstanding of how this semantics is affected by the demands the taskputs upon the subject''s cognitive system. We make novel proposals inthese terms for explaining the major content effects of deonticmaterials. Throughout we illustrate with…Read more
  •  39
    Reasoning in Non-probabilistic Uncertainty: Logic Programming and Neural-Symbolic Computing as Examples
    with Tarek R. Besold, Artur D’Avila Garcez, Keith Stenning, and Leendert van der Torre
    Minds and Machines 27 (1): 37-77. 2017.
    This article aims to achieve two goals: to show that probability is not the only way of dealing with uncertainty ; and to provide evidence that logic-based methods can well support reasoning with uncertainty. For the latter claim, two paradigmatic examples are presented: logic programming with Kleene semantics for modelling reasoning from information in a discourse, to an interpretation of the state of affairs of the intended model, and a neural-symbolic implementation of input/output logic for …Read more
  •  1
    The Proper Treatment of Events
    with Fritz Hamm
    Bulletin of Symbolic Logic 12 (1): 139-141. 2006.
  •  52
    A logic of vision
    with Jaap M. van der Does
    Linguistics and Philosophy 23 (1): 1-92. 2000.
    This essay attempts to develop a psychologically informed semantics of perception reports, whose predictions match with the linguistic data. As suggested by the quotation from Miller and Johnson-Laird, we take a hallmark of perception to be its fallible nature; the resulting semantics thus necessarily differs from situation semantics. On the psychological side, our main inspiration is Marr's (1982) theory of vision, which can easily accomodate fallible perception. In Marr's theory, vision is a m…Read more
  •  102
    Executive function has become an important concept in explanations of psychiatric disorders, but we currently lack comprehensive models of normal executive function and of its malfunctions. Here we illustrate how defeasible logical analysis can aid progress in this area. We illustrate using autism and attention deficit hyperactivity disorder (ADHD) as example disorders, and show how logical analysis reveals commonalities between linguistic and non-linguistic behaviours within each disorder, and …Read more
  •  8
    Event Calculus, Nominalisation, and the Progressive
    with Fritz Hamm
    Linguistics and Philosophy 26 (4): 381-458. 2003.
  •  67
    Logic as Marr's Computational Level: Four Case Studies
    with Giosuè Baggio and Peter Hagoort
    Topics in Cognitive Science 7 (2): 287-298. 2015.
    We sketch four applications of Marr's levels-of-analysis methodology to the relations between logic and experimental data in the cognitive neuroscience of language and reasoning. The first part of the paper illustrates the explanatory power of computational level theories based on logic. We show that a Bayesian treatment of the suppression task in reasoning with conditionals is ruled out by EEG data, supporting instead an analysis based on defeasible logic. Further, we describe how results from …Read more
  •  43
    Sieg has proposed axioms for computability whose models can be reduced to Turing machines. This lecture will investigate to what extent these axioms hold for reasoning. In particular we focus on the requirement that the configurations that a computing agent (whether human or machine) operates on must be ’immediately recognisable’. If one thinks of reasoning as derivation in a calculus, this requirement is satisfied; but even in contexts which are only slightly less formal, the requirement cannot…Read more
  •  36
    Interpretation is the process whereby a hearer reasons to an interpretation of a speaker's discourse. The hearer normally adopts a credulous attitude to the discourse, at least for the purposes of interpreting it. That is to say the hearer tries to accommodate the truth of all the speaker's utterances in deriving an intended model. We present a nonmonotonic logical model of this process which defines unique minimal preferred models and efficiently simulates a kind of closed-world reasoning of pa…Read more
  •  41
    The representation of Takeuti's *20c ||_ -operator
    with Roger M. Cooke
    Studia Logica 42 (4). 1983.
    Gaisi Takeuti has recently proposed a new operation on orthomodular lattices L, ⫫: $\scr{P}(L)\rightarrow L$ . The properties of ⫫ suggest that the value of ⫫ $(A)(A\subseteq L)$ corresponds to the degree in which the elements of A behave classically. To make this idea precise, we investigate the connection between structural properties of orthomodular lattices L and the existence of two-valued homomorphisms on L
  •  755
    In this article we provide a mathematical model of Kant?s temporal continuum that satisfies the (not obviously consistent) synthetic a priori principles for time that Kant lists in the Critique of pure Reason (CPR), the Metaphysical Foundations of Natural Science (MFNS), the Opus Postumum and the notes and frag- ments published after his death. The continuum so obtained has some affinities with the Brouwerian continuum, but it also has ‘infinitesimal intervals’ consisting of nilpotent infinitesi…Read more
  •  53
    Discourse processing in attention-deficit hyperactivity disorder (adhd)
    with Claudia van Kruistum and Esther Parigger
    Journal of Logic, Language and Information 17 (4): 467-487. 2008.
    ADHD is a psychiatric disorder characterised by persistent and developmentally inappropriate levels of inattention, impulsivity and hyperactivity. It is known that children with ADHD tend to produce incoherent discourses, e.g. by narrating events out of sequence. Here the aetiology of ADHD becomes of interest. One prominent theory is that ADHD is an executive function disorder, showing deficiencies of planning. Given the close link between planning, verb tense and discourse coherence postulated …Read more
  •  37
    This reply to Oaksford and Chater’s ’s critical discussion of our use of logic programming to model and predict patterns of conditional reasoning will frame the dispute in terms of the semantics of the conditional. We begin by outlining some common features of LP and probabilistic conditionals in knowledge-rich reasoning over long-term memory knowledge bases. For both, context determines causal strength; there are inferences from the absence of certain evidence; and both have analogues of the Ra…Read more
  •  16
  •  80
    Language, linguistics and cognition
    with Giosue Baggio and Peter Hagoort
    In Ruth M. Kempson, Tim Fernando & Nicholas Asher (eds.), Philosophy of Linguistics, North Holland. 2012.